The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 02, 1999
Filed:
Jan. 30, 1998
Shahryar Rokni, Carlsbad, CA (US);
Tom A Watson, Carlsbad, CA (US);
David J Tammadge, San Diego, CA (US);
Cymer, Inc., San Diego, CA (US);
Abstract
An excimer laser with a laser gas containing fluorine in which the fluorine concentration is maintained continuously at or substantially at desired predetermined levels. A real time or substantially real time fluorine monitor provides a feedback signal to a fluorine flow control system which provides continuous fluorine injection flow into the laser chamber to precisely compensate for fluorine depletion and maintain fluorine concentration precisely at desired levels. In a preferred embodiment, fluorine detector which may be a chemical detector periodically measures the fluorine concentration in laser gas discharged from the laser in order to calibrate the real time or substantially real time fluorine monitor. In a second preferred embodiment, the continuous inlet flow is from two gas sources, one containing fluorine, a noble gas and a buffer gas and the other containing only the noble gas and the buffer gas. In a third embodiment, the continuous inlet flow is from a gas source containing fluorine, a noble gas and a buffer gas and filtered gas discharged from the laser.